Bangladesh gets new identity on bacteria as BINA scientist discovers three new bacterial species

30 Sep,2015

BAU, BdChronicle Reporter:

After conducting a six-year-long scientific research, Dr. Harun-or-Rashid, a senior scientific officer of Bangladesh Institute of Nuclear Agriculture (BINA) in Mymensingh discovered three new bacterial species in Bangladesh that creates nodule in the lentil crops and increases productivity of it. Given emphasis on the name of Bangladesh, BINA and lentil, he established three new scientific names i.e. Rhizobium bangladeshense®, Rhizobium binae® and Rhizobium lentis® for these bacteria. These names have published in “International Journal of Systematic and Evolutionary Microbiology” Journal in June, 2015, which is the only journal to recognize new bacterial species and their scientific name.

In 2009, Dr. Harun started his research on ‘Genetic Diversity of Rhizobia Nodulating Lentils’ at the Hydelbarg University, Germany. For his research purpose, Dr. Harun investigates lentil-nodulating rhizobia from the region where lentil originated (Turkey and Syria) and from regions to which lentil was introduced later (Germany and Bangladesh). Rhizobia from lentil nodules were chosen to study the genetic diversity, taxonomy and to know the nature of nodulation genes.

Lentil is not only the oldest legume crop but also the oldest of the crops that have been domesticated in the Fertile Crescent and distributed to other regions during the Bronze Age, making it an ideal model to study the evolution of rhizobia associated with crop legumes.

Rhizobial bacteria were isolated from collected nodules and four housekeeping genes (16S rRNA, recA, atpD, glnII) and three nodulation genes (nodA, nodC, nodD) were sequenced from isolated bacterial strains. Sequencing information were analyzed using phylogenetic and population genetic approaches. To supplement these approaches, DNA fingerprinting and phenotypic characterization also had done. Moreover, the symbiotic performance was assessed by nodulation and cross inoculation tests with lentil, peas and lathyrus.

From gene sequencing, DNA finger printing and phenotypic characterization, it was proven that three different lineages of rhizobia associated with lentil in Bangladesh and they are endemic in Bangladesh. To compare this result, similar experiments were conducted on lentil root-nodulating rhizobia isolated from Turkey and Syria.

From this comparative study, it was proven that four different lineages of rhizobia are associated with lentil of which three are new and endemic in Bangladesh. One lineage was found in the Mediterranean region and Central Europe. The new lineages from Bangladesh are close to Rhizobium etli and Rhizobium phaseoli, and correspond to new species in the genus Rhizobium. The single lineage from the Mediterranean and Central Europe belongs to the species Rhizobium leguminosarum. The endemic lentil grex pilosae, available in Bangladesh, may have played a significant role in the origin of these new lineages in Bangladesh.

These results were published in two famous international microbiology journal (Systematic and Applied Microbiology Journal & FEMS Microbiology Ecology Journal) in 2012 and 2014.

In second stage of research, DNA-DNA hybridization, carbon-nitrogen source utilization pattern and fatty acid pattern experiments were conducted with these new bacteria to have final conclusion. To have pinpoint conclusions, whole genome sequences of type strains were also done. From first and second stage of research, it was concluded that three new species are available in Bangladesh. Following international rules (ICNB: “International Code of Nomenclature of Bacteria” govern by ICSP: “International Committee on Systematics of Prokaryotes”) three scientific names, i.e. Rhizobium bangladeshense®, Rhizobium binae® and Rhizobium lentis® were proposed by Dr. Harun-or Rashid and published in ICSP recognized journal (IJSEM) in last month.

One hundred fifty eight samples of seven different genes from these three new species were sequenced and submitted to the GenBank (NCBI: National Center for Biotechnology Information) and obtained 158 accession numbers. Using these accession numbers anybody could find details information about these bacteria, told the researcher.

Whole genome of type strains were sequenced and submitted to the European Nucleotide Archive.

Whole genome sequences of type strains are now available for all in European Nucleotide Archive (http://www.ebi.ac.uk/ena/data/view/PRJEB7125). Two international culture preservation centers (DSMZ, Germany and LMG, Belgium) are maintaining type strains of these new species of bacteria with unique numbers (DSMZ: 29286, 29287 & 29288 and LMG: 28441, 28442 & 28443) for long time preservation, said Dr Harun.

About the newly developed bacterial species Dr Harun said different members of these three new species are promising for the productions of bio-fertilizers not only for lentil but also for pea and lathyrus cultivation. There are possibilities to produce better bio-fertilizer using different members of these new species. As a result, the use of urea fertilizer will be reduced and yield of lentil, lathyrus and peas could be increased.

This is an important research by which we are availed to contribute in basic science and added the name of Bangladesh and BINA with scientific names of bacteria. The name of Bangladesh and BINA will be known by world scientific community, added the researcher.